I joined to fix documentation as I find discrepancies between it and the program. Currently using Synfig Studio 1.0.2.
You can safely ignore anything here.
Right pointing arrow ▶ #x25b6 used for layer groups (collapsed) or small: ▸ #x25b8
Down pointing arrow ▼ #x25bc used for layer groups (open) or small: ▾ #x25be